Gas furnace and draft hood assembly



S. F. CIRICILLO GAS FURNACE ANDy DRAFT HOOD ASSEMBLY May 26, 1953 Filed March 4, 1952 Ff .f

3 Sheets-Sheet 1 Ihventov. Samuel vE Cir'icillo, b9 /w His Attor'neg.

May 26, 1953 s.- F. clmclLLo l 2,639,706

GAS FURNACE AND DRAFT Hoon. ASSEMBLY Filed March 4, 1952 5 Sheets-Sheet 2 uuuu'unuuu unnnnuuulr unuuunuu unnnuunnn Inventor:

I-Iis Attorney Samuel F. Cir'icillo,4

May 26, 1953 s. F. clRlclLLo GAs FURNACE- AND DRAFT Hoon ASSEMBLY 5 Sheets-Sheet 5 Filed March 4, 1952 a o a a a a a a a a a a a a I '/Irwervcor': Samuel FT Ciricillo,

His Attorneg.

Patented May 26, 1953 GAS FURNACE AND DRAFT HOOD ASSEMBLY Samuel F. Ciricillo, Newark, N. J., assignor vto General Electric Company, a corporation of New York Application March 4, 1952, Serial No. 274,744

(Cl. 12S- 116) 4 Claims.

This invention relates to furnaces for domestic heating systems and particularly to draft hood assemblies for such furnaces which burn gaseous fuel.

Domestic heating furnaces, and particularly those burning gaseous fuel, are provided with draft hoods to prevent blow-back of gas from the chimney or flue to the combustion unit, in order to prevent the extinguishing of the flame in the event of adverse wind conditions. It is desirable to construct domestic heating furnaces so that they occupy minimum space in the house. Obviously it is desirable that the flue connections be easily made with minimum external parts, and further it is also desirable that the flue connections can be made at any one of a plurality of positions on the wall of the furnace in order to avoid restrictions on the location of the furnace dictated by a single required flue position. Accordingly, it is an object of this invention to provide an improved draft hood assembly for domestic heating furnaces.

Another object of the invention is to provide an improved furnace including a draft hood assembly constructed to facilitate connection of the flue adjacent either of two opposite walls of the furnace. v

It is a further object of the invention to provide an improved furnace and draft hood assembly affording connection of the flue to either side of the furnace as desired and which re quires no additional parts or fittings.

Further objects and advantages of this invention will become apparent as the following description proceeds, and the features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

In carrying out the objects of this invention, a domestic heating furnace employing gaseous fuel is constructed in generally rectangular form and includes a suitable combustion chamber and heat transfer ducts or tubes through which the hot combustion gases are passed in heat exchange with the air or other fluid to be heated and circulated to the house. A draft hood assembly is built into the casing of the furnace so that it does not extend beyond the walls thereof and comprises partitions forming a passage extending entirely across the casing between openings in the respective walls of the casing, and interchangeable ttings are provided for the two ends of the passage. The portions of the fittings .are engaged in identical guide tracks at'the two lends of the passage. One of these fittings comprises a closure plate and flue connection, to gether with a baiiie for directing the combustion gases from an opening in the gas manifold to the flue, and the other of which comprises a closure plate for shutting off a corresponding opening at the other end of the passage. Two open ends of the passage formed in the Walls of the casing are provided with finished cover plates, one of which has an opening for accommodating the flue connection and the other of which is a perforate plate of grille-like form which providesra finished appearance and affords passage of the blow-back air or gas during adverse pressure conditions.l The fittings may be applied interchangeably to either side of the furnace so that location of the furnace is not restricted by a single flue connection.

For a better understanding of this invention, reference may be had to the accompanying drawings in which Fig. 1 is a side elevational view partly in section of a horizontal furnace provided with a draft hood assembly embodying the invention; Fig. 2 is a View similar to Fig. 1 on the opposite side of the furnace; Fig. 3 is an enlarged sectional view taken along the line 3-3 of Fig. 1; Fig. 4 is a sectional view taken on the line 4-4 of Fig. 3; and Fig. 5 is an exploded perspective view showing the draft hood assembly of the furnace.

Referring now to the drawings, the furnace illustrated in Figs. 1 and 2 comprises a generally rectangular casing I!) having an inlet connection II for receiving air to be heated and an outlet connection I2 for distributing heated air to the rooms of the house. A control compartment is provided below the connection I2 and may be reached through an access cover` I3 having louvers I4 therein for admitting air to the mixing openings of the gas furnace. Within the control compartment are arranged the usual controlsy (not shown), including the gas regulating valve, Aburner adjusting elements, and shut-off valves. 'I'he combustion unit comprises a chamber defined by walls 8 and having gas burners 9 arranged in the lower portion of the casing adjacent the control compartment and arranged to supply the products of combustion through heat transfer ducts or tubes I5, which may be seen in Figs. 4 and 5, to a manifold I6 extending across the casing in the upper portion thereof. The manifold I6 is connected in communication with a triangular or troughlike passage I'I formingv part of the draft VYhood assembly, and the products of combustion flow from the passage I'I to a flue connection IB andl thence to .the

chimney. The opposite end of the passage I1 is open to the atmosphere about the furnace through a perforate or grilled cover plate I9. The combustion gases owing from the manifold I6 toward the flue I8 are directed by a U- shaped baiile 2|) toward the flue to minimize turbulence within the passage I'I.

The details of construction of the draft hood assembly will be more readily apparent from a consideration of Figs. 3, 4 and 5 where it can be seen that the lower wall of the manifold I is provided with openings 2| and 22 on both sides of the casing directly above the passage |I and providing communication therewith. IIn the draft hood assembly as viewed in Fig. 3, the opening 2| provides communication between the manifold I6 and the iiue connection throughA the open top of the U-shaped baille 2t, and the opening 22 is closed by a baffle plate 23 removably attached by screws M to the outside of the casing at the edge of an opening 25 which is coextensive with the triangular end of the passage I?. The plate Etis guided into position and retained therein by a pair of parallel tracks or guides 26 which extend across the lower side of the bottom wall of the manifold i6 along the sides of the openings 2| and 22. The guides adjacent the opening 2| receive flanges 2l on the U-shaped baule 2li and guide this baie into place and retain it in its required position. The U- shaped baliie is secured to a closure plate 28 which covers a triangular opening 29 in the side wall of the casing and is detachably secured about the opening by screws 3|?. The baille is secured to the plate 28 by a plurality of lateral flanges '.i

and a flue connection I 3 comprising a circular collar or flange is also attached to the plate 29 about a circular opening 33,

In order to provide a nnished appearance of the furnace casing adjacent the draft hood assembly, a cover plate 34 is provided adjacent the flue connection and has a circular opening 35 registering with and affording access to the flue connection. The cover plates I9 and 34 .are of the same general dimensions and may be interchangeably secured to the outside of the casing, each of the plates having in-turned flanges, and the upper portions of the plates I9 and 3d having down-turned flanges 3S and 3'! respectively which engage slots formed by strips 38 and 39 respectively secured to the outer wall of the casing. After the upper ends of the cover plates have been secured in their respective slots the lower ends are snapped over resilient lugs d and 4I respectively, screw heads 42 and 133 being engaged by formed bumps or recesses on the lugs, as shown. As shown by the arrows in the drawings, combustion gases flow to the manifold IB from the ducts I through openings along one side of the manifold and flow horizontally through the manifold to the opening 2| above the passage I'I and thence through the opening 2 I, they being directed by the baie 20 so that there is minimum turbulence in the passage II, and thence out the flue connection I8 to the chimney. Should adverse pressure conditions occur so that there is a blow-back of air or gas from the chimney, the blow-back gases would pass directly through the baffle 2U toward the opposite end of the passage I1 and out of the casing through the grilled plate I9, thereby preventing blow-back through the manifold I6, the direction of the blow-back gases being such that there normally is no tendency of the blow-back gas to flow into the manifold, and in View of the velocity effects adjacent 4 the opening 2| the tendency is rather to educt gases from the manifold and entirely prevent blow-back to the burners and possible extinguishing of the llame. The manner in which draft hoods operate is well known in the art.

Should it be desired to connect the flue to the right-hand side of the furnace as viewed in Fig. 3, the cover plates and the screws 24 and 30 are removed and the closure plate and baffle slid out of engagement with the guides and the plate 23 is also removed. These parts can then be interchanged, the bale 2t being inserted on the guides 26 in the right-hand opening 25 of the furnace, and the plate 23 'being inserted in the guides 2E in the left-hand side to Close the outlet opening 2l of the manifold. The screws 24 and 3d are then replaced, together with the cover plates, whereupon the furnace may be connected to the chimney at the right-hand side, communication between the manifold and the chimney then being had throughthc outlet opening v22 in the wall of the manifold.

It is thus apparent that astructurally simple draft hood assembly has been provided which facilitates the connection of the flue to either side of the furnace and requires no additional parts or fittings and, further, involves no draft hood extensions or fittings extending beyond the wall of the furnace. Ready interchangeability is particularly desirable for furnaces manufactured in mass production and which are designed for installation in minimum space. Applicants invention, which provides a simple and effective draft hood arrangement for selectively connecting the flue to either side of the furnace, greatly facilitates the installation procedure and requires mlninnun installation time for adapting the furnace to locations with differing space and location requirements. y

While the invention has been illustrated in connection with a particular form of warm air furnace, other applications will readily be apparent to those skilled in the art. Therefore, it is not desired that the invention be limited to the detailed construction illustrated and described, and it is intended by the accompanying claims to cover all modications within the spirit and scope of the invention.

What I claim as new and desire to be secured by Letters Patent of the United States is:

l. A furnace comprising a rectangular casing having a fuel combustion unit therein, means providing 'a chamber extending substantially across said casing between two opposite side walls thereof for receiving combustion gases from said unit, a draft hood assembly in said casing adiacent said chamber for removing combustion gases from said chamber and for preventing blow-back of gas from outside said casing to said unit, said assembly comprising a duct extending across said casing between said two sides and having open communication with said chamber near both ends, said opposite side walls having openings at the ends of said duct providing communication with the exterior of said casing, a closure plate for one of said openings in said walls, a flue connection formed in said plate, a U-shaped baile secured to said plate in surrounding relation to said flue connection, flanges on said baffle at the ends of the U, guide tracks on the wall of said chamber adjacent one end for receiving said anges and for removably retaining said U -shaped bafe in position adjacent the opening at said one end between saidchamber andsaid duct, a baille plate for closing the opening between said chamber and said duct at the other end of said duct, guide tracks on the wall of said chamber adjacent said other end for receiving the edges of said baie plate and for removably retaining said baile plate in position, said U-shaped baffle facilitating the directing of combustion gases into said flue connection during normal operation oi' the furnace and providing a direct line path from said ilue connection to the exterior of said casing through said duct for blow-back of gas from said flue during reverse flow conditions and said Ibaffle plate preventing blow-back to said unit through said other end of said duct, said guides being of substantially the same spacing at both ends of said duct whereby said U-shaped baille and said baille plate may be located interchangeably at either end ol said duct.

2. A furnace according to claim 1 including detachable and interchangeable cover plates for the openings in the walls of said casing, one oi" said cover plates having an opening to afford access to said hue connection and the other of said plates being perforate to afford discharge of blowbaci; gases from said duct.

3. A draft hood assembly for gas iurances and the like comprising means providing a substantially rectangular gas manifold having inlet openings along one wall for admitting combustion gas thereto and a pair of spaced outlet openings remote from said inlet openings, means providing an open-ended passage coeXtensive with said manifold and communicating near its respective ends with said outlet openings, a detachable closure plate having a iiue fitting therein mounted at one end of said passage for closing said end, a U-shaped -baie attached to the inner wall of said plate in surrounding relation to said fiue connection and having the open end of the U toward the adjacent one of said outlet openings, flanges on said baille at the ends of the U, guide means on said manifold along two sides of said adjacent outlet opening for slidably receiving said flanges, similar guide means at the other end of said passage at the sides of the other of said outlet openings, a baile sheet slidably mounted in said similar guide means for closing said other outlet opening, said baie sheet and said U-shaped baiiie being interchangeable, and means at said other end of said passage for 6 detachably securing said plate at said other end whereby said baille sheet and said closure plate may be mounted interchangeably at either end of said passage.

4. A furnace comprising a rectangular casing having a fuel combustion unit therein, a plurality of heat transfer conduits extending upwardly from said unit for conducting combustion gas therefrom, means providing a shallow rectangular manifold chamber in the upper portion of said casing and having inlet openings communicating with said ducts, said manifold having a pair of spaced outletsin the lower Wall thereof near the opposite Walls of said casing remote from said inlet openings, a trough below said manifold and extending across said casing to provide a passage in communication with both said outlets, said casing having openings therein at both ends of said trough substantially coextensive therewith, a closure plate having a flue connection therein and interchangeably tting the openings in the casing at both ends of said trough, a U-shaped baite attached to said plate in surrounding relation to said flue connection and having iianges at the ends of the U positioned to lie adjacent the respective sides of one of said outlets when said closure plate is in position, said bafe deecting gas discharged from said manifold through said outlet toward said flue connection, parallel guide members on said manifold and extending along the sides of said outlets for receiving and guiding said flanges, and a baiile plate dimensioned to fit in said guides and close either of said outlet openings whereby said plate and said baie are interchangeable and said plate prevents communication between said manifold and said trough at the end of said passage opposite said nue connection and directs blow-back gas through said passage to the opening in said casing.

SAMUEL F. CIRICILLO.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,180,212 Morrow Nov. 14, 1939 2,277,201 Belt Mar. 24, 1942 2,313,933 Goerg Mar. 16, 1943 2,582,071 Schultz Jan. 8, 1952 

